The present invention relates to pneumatic operated motors, and in particular to a motor that uses compressed fluid or air to power the motor. A pneumatic motor may be used in a wide variety of applications, from wheeled vehicles to propeller operated airplanes and helicopters, as well as air powered boats. In addition, other applications in various other fields of use are just now being realized, such as any air powered or battery powered product.
One problem in the prior art, which is realized and solved by the present invention, is simplicity. The ability to provide an efficient pneumatic motor without the need of complicated intake and exhaust ports, spring operated pistons, valve rods, piston connection rods, individual seals, specially designed seal skirts, complicated drive axle mountings, etc. All of which complicates the manufacturing of the pneumatic motor and increases the likelihood that an individual part will break making the motor inoperable. As such a need exists to improve upon the prior art pneumatic motors. Such an improvement should simplify the manufacturing by eliminating the need for complicated mechanisms, additional rods, seals, springs and etc. such an improvement will further provide for pneumatic motors that may be made smaller, lighter and less expensive than other prior art motors.
For example, U.S. Pat. No. 4,329,806 to Akiyama discloses a fluid engine for use in pneumatic operated toys. The ""806 patent uses a complicated structure that includes a intake valve rod that is connected to a disc element that is also connected to a parallel drive axle. A piston, perpendicular to the drive axle and the valve rod, is in communication with the disc element that is rotated by the upward and downward movement of the piston. The disc element also includes a profile surface in contact with the valve rod. When the disc element rotates, the profile surface causes the valve rod to move inwardly, when the piston is moving upwardly, and to move outward, when the piston is moving downwardly. In addition, when the valve rod moves inwardly, fluid or compressed air enters the chamber. The air pushes the piston upwards and eventually expels out of a side exhaust. The inertia in the drive axle caused of the upward movement of the piston will continue to move the piston downwards such that the process will continue, until the air runs out.
U.S. Pat. No. 6,006,517 to Kowanacki utilizes a compressed spring to close an intake valve, where air enters into the cylinder or chamber. A valve member is pushed upwardly by the compressed spring against an aperture creating a air tight seal. A piston moving downwards pushes the member down passed an intake valve, allowing compressed air to flow over the member through the aperture into a chamber. The air pushes the piston up causing a drive axle attached thereto to rotate. Once the piston is moved up the compressed spring pushes the member back up closing the intake valve. Moreover, the air entering the chamber with the piston escapes out of side exhaust ports (cut into the chamber) when the piston reaches the top position. U.S. Pat. No. 6,085,631 utilizes the same principles in the ""517 patent except it introduces a low/high pressure seal that expands when air is pressed up against it.
In addition it is well known that when manufacturing, the size of the product will be dependent upon all of the parts. If a pneumatic motor is desired to be extremely small, say the size of about an inch in length or less, it would be virtually and/or practically impossible using the pneumatic motors of the prior art to manufacture all of the parts small enough and assembly the same to fit this size. A benefit realized by the pneumatic motor of the present invention was found that the size could be made extremely small because of the simplicity of the present invention.
However on the other extreme, because of the simplicity it is also extremely easy to make the pneumatic motor larger. As such, the present invention finds applicability in compressed fluid-powered engines used for operating automobiles, such as described by U.S. Pat. No. 6,006,519. The ""519 patent discloses a compressed air-powered engine designed for use in an internal combustion engine, using a xe2x80x9cWankel-type rotary engine.xe2x80x9d
In accordance with the present invention a pneumatic motor is provided. The pneumatic motor includes at least one piston, each of which is attached to a crank shaft such that when the piston moves upwardly and downwardly an axle attached to the crank shaft rotates therewith. The pneumatic motor includes a housing having a cylinder for each piston. Each cylinder is in fluid communication with a corresponding intake channel in the housing that is also in fluid communication with an intake chamber. Each cylinder further has a corresponding exhaust through the top portion of the housing. Each intake channel houses a member that seals the corresponding cylinder from the intake channel when compressed fluid initially enters the intake channel or when the pressure in the intake channel is greater then the pressure in the cylinder.
Each piston is preferably defined by a single rigid piece that has a connecting rod extending upwardly to attach to the crank shaft, an actuator that extends downwardly to contact and push the member, and has a section with a diameter that is defined to create a temporary or artificial fluid seal against the corresponding cylinder wall. As mentioned above, extending downwardly from each piston is an actuator that has a profile or camber defined such that the actuator may exert a force against the member sufficient to push the member into the intake channel allowing compressed fluid in the intake channel to enter the corresponding cylinder.
The piston also includes a section that has a diameter that is defined to create a temporary or artificial fluid seal against the corresponding cylinder wall, such that compressed fluid entering the corresponding cylinder via the intake channel cannot initially escape. As such, the compressed fluid exerts a force against the section pushing the cylinder upwardly. The section further includes exhaust grooves formed therein and positioned such that the fluid seal is created only during upward movement of the piston and the fluid seal is broken during downward movement of the piston. This is caused because during the upward and downward movement of the piston, the connecting rod is a rigid extension of the piston that connects to a rotating crank shaft, such that the piston also pivots within the cylinder. When the fluid seal is temporarily broken, compressed fluid in the cylinder below the section escapes upwardly past the section and out through the exhaust. This also causes the compressed fluid in the intake channel to push the member back against the cylinder ensuring that the member re-seals the cylinder from the intake channel.
Inertia from the crank shaft, caused by the upward stroke of the piston, continues to move the piston through the downward stroke into a position in the upward stroke that causes the actuator to contact and push the member inwardly allowing the compressed fluid to reenter the cylinder. Thereby creating a cycle that will continue as long as the supply of compressed fluid to the intake channel(s) is maintained.
The present invention may be designed as small as manufacturing allows as well as large as desired. The present invention may therefore find applicability in full-scale air compressed engines that may be used in vehicles, planes, boats, helicopters, as well as miniature-scaled engines used to operate toys and/or other consumer or industrial air powered or battery powered products.